Figure 6

Adsorption kinetics of (a,b) methylene blue and (c,d) congo red by TACs at concentrations of (a,c) 20 mg/L and (b,d) 100 mg/L (adsorbent mass: 50 mg, solution volume: 50 mL, contact time: 2–540 min at room temperature; lines were predicted by pseudo-second-order model).